UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS 


COLLEGE  OF  AGRICULTURE 

AGRICULTURAL  EXPERIMENT  STATION 

BERKELEY,  CALIFORNIA 


JOG  CHOLERA  AND  PREVENTIVE  SERUM 


BY 

F.  M.  HAYES 


BULLETIN  No.  229 

BERKELEY,  CALIFORNIA,  AUGUST,  1912 


Friend  Wm.  Richardson,  Superintendent  op  State  Printing 

sacramento,  california 

1912 


Benjamin  Ide  Wheeler,  President  of  the  University. 

EXPERIMENT  STATION  STAFF. 

E.  J.  WlCKSON,  M.A.,  Director  and  Horticulturist. 

E.  W.  Hilgard,  Ph.D.,  LL.D.,  Chemist   (Emeritus). 

W.  A.  Setchell,  Ph.D.,  Botanist. 

Leroy  Anderson,  Ph.D.,  Dairy  Industry. 

A  I.    E.  Jaffa,  M.S.,  Nutrition  Expert. 

i:     II.   Doughridge,   Ph.D.,   Soil  Chemist  and  Physicist    (Emeritus). 

C.   W.   Wiiodworth,  M.S.,  Entomologist. 

Ralph   E.   Smith,   B.S..    Plant    Pathologist  and   Superintendent   of   Southern   California 

Pathological   Laboratory  and  Experiment  Station. 
P.  R.  Marshall,  B.S.A.,  Animal    Industry. 
G.    W.    Shaw,   M.A.,    Ph.D.,    Experimental   Agronomist    and   Agricultural    Technologist, 

in  charge  of  Cereal  Stations. 

B.  A.  Etcheverry,  B.S.,  Irrigation   Expert. 
P.  T.  Bioletti,  M.S.,  Viticulturist. 

W.  T.  Clarke,  B.S.,  Assistant  Horticulturist  and  Superintendent  of  University  Exten- 
sion in  Agriculture. 
John  S.   Burd,  B.S.,  Chemist,   in  charge  of  Fertilizer  Control. 
J.   E.  Coit,  Ph.D.,   Pomologist,   Riverside. 

C.  B.    Lipman,  Ph.D.,   Soil  Chemist  and  Bacteriologist. 

George    E.    Colby,    M.S.,    Chemist    (Fruits,    Waters,    and    Insecticides),    in    charge    of 

Chemica  l  Laboratory. 
H.  J.  Qliayle,  M.S.,  Assistant  Entomologist. 
H.  M.    Hall,  Ph.D.,   Assistant  Botanist. 
C.  M.   Hauing,   D.V.M.,    Veterinarian  and   Bacteriologist. 
E.  B.  Babcock,  B.S.,  Agricultural  Education. 
W.   B.   Herms,  M.A.,  Assistant  Entomologist. 
W.  T.   Horne,  B.S.,  Assistant  Plant  Pathologist. 
1,.  M.   Davis,  B.S.,  Assistant   Dairy  Industry. 
W.    W.   Bonns,  M.S.,   Assistant    Pomologist. 

A.  J.  Gaumnitz,  M.S.,   Assistant  Agronomist,    University  Farm,   Davis. 
T.  F.  Hunt,  B.S.,  Assistant  Plant  Pathologist. 
P.  L.  McCreary,  B.S.,  Chemist  in  Fertilizer  Control. 
E.  H.  Hagemann,  Assistant  in  Dairying,  Davis. 
R.  M.  Roberts,  Farm  Manager,  University  Farm,  Davis. 
J.  I.  Thompson,  B.S.,  Assistant  Animal  Industry,  Davis. 
J.  C.  Bridwell,  B.S.,  Assistant  Entomologist. 
L.  Bonnet,  I.  A.,  Assistant  Viticulturist. 

P.  C.  H.  Flossfeder,  Assistant  in  Viticulture,  University  Farm,  Davis. 
P.  L.  Hibbard,  B.S.,  Assistant  Fertilizer  Control  Laboratory. 
C.   H.  McCharles,  M.S.,  Assistant  Agricultural  Chemical  Laboratory. 
II.   A.   Madson,  B.S.A.,   Assistant  Experimental  Agronomist. 

Walter  E.  Packard,  M.S.,  Field  Assistant  Imperial  Valley  Investigation,  El  Centre 
S.    S.    Rogers,  B.S.,   Assistant   Plant   Pathologist,    Plant  Disease   Laboratory,    Whittier. 
C.  O.  Smith,  M.S.,  Assistant  Plant  Pathologist,  Plant  Disease  Laboratory,  Whittier. 

E.  H.  Smith,  M.S.,  Assistant  Plant  Pathologist. 

C.  L.   Roadhouse,  D.V.M.,  Assistant  in  Veterinary  Science. 

F.  M.    Hayes,  D.V.M.,  Assistant  Veterinarian. 
P.   S.  Burgess,  M.S.,  Assistant  Soil  Chemist. 
W.   P.  Gericke,  B.S.,  Assistant  Soil  Chemist. 

M.  E.  Stover,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 

W.    H.  Volck,  Field  Assistant  in  Entomology,  Watsdnville. 

E.  L.  Morris,  Field  Assistant  in  Entomology,  San  Jose. 

E.  E.  Thomas,  B.S.,  Assistant  Chemist,  Plant  Disease  Laboratory,  Whittier. 

A.   B.   Shaw,  B.S.,   Assistant  in  Entomology. 

<;.   P.   Gray,  M.S.,  Chemist  in  Insecticides. 

H.    D.    Young,   B.S.,    Assistant   in    Agricultural    Chemistry,    Plant   Disease    Laboratory, 

Whittier. 
A.  R.  Tylor,  B.S.,  Assistant  in  Plant  Pathology,  Plant  Disease  Laboratory,  Whittier. 
W.   V.  Cruess,  B.S.,  Assistant  in  Zymology. 

J.   F.   Mitchell,  D.V.M.,   Assistant  in   Veterinary  Laboratory. 
W.  A.  Boys,  B.S.,  Assistant  Cerealist. 
M.   R.  Miller,  B.S.,  Assistant  Chemist  in  Insecticides. 
P.  H.  Wilson,  B.S.,  Assistant  in  Soil  Chemistry. 
W.  M.  Mertz,  Assistant  in  Pomology,  Riverside. 

Anna  M.  Lute,  A.B,r  Scientific  Assistant,  U.  S.  Dept.  of  Agriculture. 
J.  C.  Roper.  Patron,  University  Forestry  Station,  Chico. 
E.  C.  Miller,  Foreman.  Forestry  Station,  Chico. 

D.  L.   Bunnell,  Secretary  to  Director. 


HOG  CHOLERA  AND  PREVENTIVE  SERUM. 


Hog  cholera  has  for  many  years  been  the  greatest  menace  facing  the 
swine  industry.  Were  it  not  for  this  disease,  hog  raising  would  be  one 
of  the  most  profitable  branches  of  the  live  stock  business.  Those  who 
have  escaped  its  effects  are  indeed  fortunate.  Next  to  tuberculosis  in 
hogs  more  hogs  have  been  condemned  for  hog  cholera  under  federal 
inspection  than  for  any  other  cause.  However,  this  does  not  give  any 
fair  idea  of  the  loss  from  hog  cholera,  because  it  is  only  a  few  of  such 
affected  hogs  that  ever  live  to  reach  the  abattoir,  while  the  tuberculous 
hogs  may  not  show  evidence  of  tuberculosis  until  slaughter.  It  may  be 
estimated  that  85  per  cent  of  all  the  losses  from  death  or  lack  of  proper 
development  in  hogs,  are  produced  by  hog  cholera.  California  does 
not  produce  sufficient  pork  to  supply  the  domestic  demand.  Not  all  of 
the  territory  comprising  the  State  is  by  any  means  suitable  to  the  hog 
industry ;  but,  nevertheless,  there  is  opportunity  for  a  great  increase  in 
the  production  of  hogs  under  present  conditions,  and  with  the  develop- 
ment of  new  territory  through  the  introduction  of  irrigation,  this 
should  be  one  of  the  most  profitable  branches  of  stock  raising.  That 
California  is  not  raising  a  proportionate  number  of  hogs  is  no  doubt 
influenced  by  losses  that  have  occurred  because  of  hog  cholera.  The 
Experiment  Station  receives  many  letters  every  day  from  hog-raisers  of 
the  State,  asking  information  concerning  this  disease,  its  symptoms  and 
treatment.  This  bulletin  is  prepared  to  supply  such  information  as 
will  enable  the  farmer  to  familiarize  himself  with  the  symptoms  of  hog 
cholera,  the  principles  of  sanitation  before  and  during  outbreaks,  and 
the  use  of  anti-hog  cholera  serum,  so  that  the  disease  may  be  prevented, 
or  at  least  early  cases  recognized,  and  appropriate  measures  taken  to 
prevent  extensive  dissemination. 

Cause  of  hog  cholera. 

The  specific  cause  of  hog  cholera  is  a  germ  so  small  that  it  can  not 
be  seen  by  use  of  a  microscope.  The  organisms  pass  through  the  finest 
filters  and  cannot  be  artificially  grown  in  the  laboratory.  The  blood 
and  excretions,  especially  the  urine  and  feces  of  a  hog  sick  with  cholera, 
are  capable  of  producing  the  disease  in  a  susceptible  hog.  The  virus 
(blood  of  a  sick  hog)  is  highly  infectious. 

The  accessory  causes  of  hog  cholera  are  numerous  and  include  all 
conditions  that  weaken  the  constitution  and  natural  resistance  to  disease, 
such  as:  (1)  improper  feeding,  which  includes  unbalanced  rations, 
over  feeding,  insufficient  food,  irritating  food — as  garbage  and  fer- 
mented slops  are  likely  to  be — and  insanitary  feeding  troughs  and 


Z  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

floors;  (2)  impure1  drinking  water.  A  hog  requires  clean  water  just 
as  much  as  any  animal.  Stagnant,  warm  and  dirty  water  in  which  the 
hog  bathes  should  not  be  given  him  to  drink.  This  may  be  conservation 
of  water  but  not  of  health;  (3)  insufficient  protection  from  the  heat 
in  summer  and  from  the  cold  and  dampness  during  the  winter  brings 
about  disorders  that  may  render  a  hog  susceptible  to  cholera;  (4)  insan- 
itary condition  of  yards,  houses  and  farrowing  pens.  Many  forms  of 
bacterial  life  develop  in  insanitary  environment.  Lice  and  worms  are 
a  menace  to  the  health  of  the  hog;  (5)  crowding  hogs  in  sleeping  quar- 
ters causes  unhealthy  conditions.  Hog  cholera  cannot  be  produced 
except  through  infection  with  the  specific  virus,  but  these  accessory 
causes  increase  the  susceptibility  to  this  virus. 


Fig.   1. — Insanitary  hogpen  and  wallow. 
Period  of  incubation  and  susceptibility. 

The  period  of  incubation,  which  is  the  time  between  the  exposure 
to  the  disease  and  the  appearance  of  symptoms,  may  vary  from  four 
days  to  two  weeks,  depending  upon  the  virulence  of  the  infecting 
material  and  the  natural  resistance  of  the  hogs.  Young  hogs  are  more 
susceptible  to  cholera  than  older  hogs.  Fat  hogs  which  are  heavily 
fed  and  closely  penned  show  less  resistance  than  other  types.  All 
breeds  of  hogs,  including  the  mule-foot,  are  about  equally  susceptible 
to  cholera,  though  individuals  in  any  herd  are  occasionally  found  to 
be  immune.  The  disease  may  be  very  acute  at  the  beginning  of  an 
outbreak  and  the  infecting  material  become  less  virulent  after  passing 
through  several  animals. 


Bulletin  229] 


HOG    CHOLERA    AND    PREVENTIVE    SERUM. 


3 


Symptoms. 

Although  the  symptoms  of  hog  cholera  vary  in  different  outbreaks 
and  in  different  individuals  in  the  same  herd,  due  no  doubt  to  varying 
conditions  of  feeding,  watering,  handling,  climate,  season,  housing, 
natural  resistance,  and  mixed  infections,  there  are  a  few  symptoms  of 
which  the  hog  raiser  may  be  suspicious  and  lesions  of  which  he  may 
be  certain. 

The  most  common  symptoms  are  loss  of  appetite,  lassitude,  and  a 
disposition  to  lie  with  the  head  under  the  litter.  There  is  no  desire  to 
follow  the  herd  in  feeding.  The  back  may  be  arched  and  the  bristles 
erected.  Accompanying  this  there  may  a  cough  and  a  discharge  from 
the  eyes  and  nose.     In  dusty  pens,  or  if  the  hog  has  access  to  muddy 


Fig.  2. — Hog  sick  with  cholera. 

water,  this  discharge  from  the  eyes  becomes  hardened,  completely  closing 
the  eyes,  and  causing  an  irritation  which  often  results  in  loss  of  sight. 
During  this  time  the  bodily  temperature  has  risen;  constipation,  or 
diarrhoea,  usually  of  a  yellowish  color,  is  present,  and  the  hog  has 
difficulty  in  supporting  himself  upon  his  hind  legs,  swaying  from  side  to 
side  as  he  attempts  to  walk.  His  head  and  ears  hang  down,  exhibiting 
the  general  appearance  of  little  energy. 

Inflammation  of  the  ears  and  skin  with  extensive  sloughs  rarely 
occurs.  Heart  beats  and  respirations  are  usually  quickened.  The 
breathing  may  be  very  labored  in  cases  where  the  lungs  and  lining  of 
the  chest  cavity  are  diseased.     In  the  acute  form,  which  lasts  from  a 


4  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 

few  days  to  a  week,  the  skin  along  the  belly  and  behind  the  ears  and 
between  the  thighs  often  shows  a  purplish  red  discoloration.  The 
chronic  form  may  show  all  of  the  symptoms  of  the  acute  type  but  in  a 
less  degree,  and  may  continue  from  two  weeks  to  two  months,  sometimes 
ending  in  recovery. 
Post-mortem  appearance. 

All  farmers  should  either  post-mortem  every  hog  that  dies  under 
circumstances  at  all  suspicious,  or  have  the  work  done  by  a  competent 
veterinarian  who  should  be  able  to  recognize  any  lesions  indicating  the 
presence  of  an  infectious  disease  in  the  herd.     These  conditions,  if  recog- 


Fig.  3. — The  appearance  of  the  kidneys  in  some  cases  of  hog  cholera. 

nized  early  and  proper  methods  of  isolation  instituted,  might  prevent  the 
general  dissemination  of  the  disease  throughout  the  herd. 

In  cases  of  hog  cholera  the  lesions  will  vary  according  to  the  course 
of  the  disease,  but  the  following  are  usually  present :  Slight  inflamma- 
tion of  the  bladder  is  shown  by  redness  of  its  lining;  hemorrhagic 
spots  on  the  kidneys  varying  in  size  from  the  point  to  the  head  of  a  pin. 
The  kidneys  are  often  pale  and  light  colored  showing  these  black  spots, 
but  may  be  dark  and  congested.  The  kidneys  may  be  thickly  covered 
with  these  spots,  or  possibly  only  a  few  of  them  may  be  seen  by  stripping 
off  the  envelope  of  the  kidney.     The  kidneys  sometimes  resemble  a 


Bulletin  229]  H0G    CHOLERA   AND   PREVENTIVE    SERUM.  5 

turkey  egg  in  appearance.  The  spleen  is  usually  enlarged,  congested, 
black  and  friable.  Inflammation  of  the  intestines,  more  especially  the 
mucous  membrance  of  the  caecum,  the  beginning  of  the  large  intestine, 
often  occurs.  This  inflammation  may  be  diffuse  or  in  the  form  of 
ulcers,  depending  upon  whether  the  acute  or  the  chronic  type  of  the 
disease  exists.  The  presence  of  button-shaped  ulcers  in  the  large  intes- 
tines is  the  best  indication  of  chronic  cholera.  The  outer  covering  of 
the  intestines  may  show  red  blotches  in  the  acute  type.  Diffuse  inflam- 
mation of  the  inner  surface  of  the  stomach,  congestion  of  the  lymphatic 
glands  along  the  intestines  and  between  the  lungs,  haemorrhagic  spots 
on  the  lungs  varying  from  one  eighth  inch  to  entire  congestion  of  all 
the  lobes  with  accompanying  loss  of  function,  are  frequently  seen. 

In  the  highly  acute  form  the  lungs  may  show  very  little  change  except 
possibly  a  few  red  spots.  In  the  less  acute  form  parts  of  the  lung 
resemble  liver  tissue  and  in  chronic  cases  may  be  filled  with  pus  with 
adhesions  to  the  chest  walls.  Inflammation  of  the  covering  of  the  heart 
may  also  exist.  Examination  for  these  changes  should  be  made  as 
soon  as  possible  after  death  of  the  animal.  Diagnosis  may  be  made  more 
certain  by  destroying  a  very  sick  pig  and  making  an  immediate  exam- 
ination. 

In  making  post-mortems  a  quantity  of  disinfectant  should  always  be 
near  by  so  that  the  hands  may  be  disinfected  thoroughly  after  the 
operation  or  in  case  of  accidental  cuts,  immediately,  to  prevent  blood 
poisoning  or  other  infection. 

The  following  table  shows  the  organs  which  should  be  examined  when 
hog  cholera  is  suspected.  A  description  of  the  appearance  of  the 
organs  in  cases  of  cholera  is  given  after  each  organ.  It  must  be 
remembered  that  all  of  these  post-mortem  appearances  may  not  be 
found  in  one  hog.  Those  in  the  skin,  large  intestine,  small  intestine, 
spleen,  kidneys  and  lungs  are  the  most  diagnostic. 

Skin Red  or  purple  discoloration  along  belly  and  between    the  hams. 

Ulcers  may  appear  and  the  skin  crack  and  ears  slough. 
Large  intestines External    congestion    and    internal    congestion    with    haemorrhagic 

spots  in  the  acute  form,  and  ulcers  in  chronic  cholera. 
Small  intestines External  and  internal  congestion.     Sometimes  haemorrhagic  spots. 

Seldom  ulcers. 
Kidneys Pale  or  dark  in  color,  with   reddish-black  spots  on   the  external 

surface.     May  resemble  a  turkey  egg  in  appearance. 

Spleen Enlarged,  black,   friable.     Sometimes  resembles  black  jam. 

Liver Seldom  any  visible  changes.     May  be  enlarged  and  congested. 

Stomach Congestion  on  mucous  lining  in  varying  degrees. 

Bladder Congestion  and  hemorrhagic  spots  on  mucous  surface. 

Lymphatic  glands — Varying  degrees  of  congestion,  from  pink  to  dark  in  color. 
Lungs May  be  covered  with  haemorrhagic  spots  of  red  or  brown  color 

varying  in  size  from  a  pin  head  to  a  half  dollar.     Complete 

hardening  of  parts  of  the  lung  occurs.     Pus  may   form,   and 

adhesions  to  the  chest  wall  sometimes  take  place. 
Heart Sometimes  shows  small  areas  of  congestion  of  the  base. 


6  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

How  hog  cholera  spreads. 

It  is  important  to  remember  that  hog  cholera  is  highly  infectious  and 
that  all  of  the  excretions  of  the  sick  hog  are  capable  of  producing  the 
disease.  For  this  reason  there  are  many  ways  by  which  the  disease  is 
scattered  and  may  be  avoided.  The  manure  of  the  sick  hog  is  perhaps 
largely  responsible  for  the  rapid  spread  of  the  disease,  since  this  excre- 
ment contaminates  the  pens,  houses,  and  feeding  floors,  and  is  in  contact 
with  the  hogs  at  all  times.  Various  animals  as  dogs,  rabbits,  cats, 
coyotes,  buzzards,  crows,  pigeons,  and  other  birds,  may  carry  the  germs 
to  another  herd.  Often  when  a  hog  dies  the  owner  thinks  little  of  it  and 
the  carcass  is  allowed  to  remain  in  the  pen  to  be  eaten  by  the  other  hogs. 
Or  the  carcass  is  left  in  the  field  as  a  prey  to  other  meat-eating  animals. 
This  hog  may  have  been  the  first  to  be  infected  and  die  of  hog  cholera, 
and  by  this  method  of  disposition  the  seed  is  sown  for  a  good  crop  of 
cholera  in  the  neighborhood.  In  known  outbreaks  carelessness  in  dispo- 
sition of  dead  carcasses  may  result  in  useless  spread  of  the  disease.  The 
germs  may  be  carried  on  the  shoes  or  clothing  of  any  one  handling  the 
hogs,  to  herds  subsequently  visited.  Stock  cars  used  for  shipping  hogs 
are  to  be  considered  cholera  infected  unless  thoroughly  cleaned  and  dis- 
infected, as  are  also  public  stockyards.  It  is  dangerous  for  the  farmer 
to  frequent  these  places  and  return  to  attend  to  his  own  herd  without 
first  disinfecting  at  least  his  shoes.  Show  hogs  may  bring  the  germs  of 
the  disease  to  the  farm  upon  their  return.  For  this  reason  they  should 
be  held  in  quarantine  at  least  two  or  three  weeks  before  being  allowed 
to  run  with  other  hogs.  Streams  of  water  receiving  drainage  from 
infected  pens  are  fruitful  ways  of  carrying  the  germs  of  the  disease 
to  the  other  herds  which  receive  water  from  such  sources.  Wagons 
often  used  to  carry  away  dead  hogs  may  be  unthinkingly  used  to  haul 
well  and  susceptible  hogs.  Frequently,  apparently  well  hogs  are  pur- 
chased, and  in  a  few  days  begin  to  show  symptoms  of  cholera.  If  they 
have  been  placed  immediately  with  other  hogs,  a  general  outbreak  may 
be  expected.  Knowing  the  source  of  the  cholera  germs  from  the  sick 
hogs,  the  intelligent  use  of  this  knowledge  may  prevent  extensive  out- 
breaks. 

Sanitary  law  relating  to  animals. 

In  general,  the  sanitary  laws  of  the  State  provide  that  all  contagious 
diseases  in  animals  must  be  reported  to  the  State  Veterinarian  at 
Sacramento.  It  is  a  misdemeanor  to  allow  infected  hogs  to  run  at 
large.  It  is  a  violation  of  the  law  not  to  dispose  of  carcasses  of  hogs 
dead  from  cholera,  in  such  a  manner  as  will  prevent  the  spread  of  the 
disease. 


Bulletin  22  9]  H0G    CHOLERA   AND   PREVENTIVE   SERUM.  7 

General  preventive  and  hygienic  measures. 

These  may  include  measures  to  prevent  not  only  the  introduction  of 
hog  cholera  but  also  further  extension  of  the  disease.  All  that  is  neces- 
sary to  prevent  cholera  is  to  keep  the  hogs  from  coming  in  contact  with 
the  specific  virus.  Sources  of  infection  should  then  of  course  be 
avoided.  New  stock  purchased  ought  to  be  held  in  quarantine  at  least 
two  or  three  weeks  to  give  time  for  the  evidence  of  symptoms  should  the 
hogs  be  infected.  Pens  should  not  be  located  near  public  roads  where 
hogs  may  be  driven.  Care  should  be  exercised  in  allowing  visitors  to 
come  in  contact  with  the  yards  and  hogs. 

The  general  health  of  the  hogs  must  be  considered  a  factor  in  the 
prevention  or  occurrence  of  cholera.  The  healthy  herd,  well  cared  for, 
will  often  resist  the  disease  when  other  hogs,  not  so  well  attended,  will 
contract  it.  Clean  pens,  pure  drinking  water,  clean  feeding  places, 
proper  feed  and  care,  are  factors  working  against  infection.  Plenty 
of  room,  in  dry,  well  ventilated  houses  for  sleeping  quarters  should  at 
all  times  be  provided.     The  yard  should  be  well  drained. 

The  lousy  hog  is  more  susceptible  to  cholera  because  lice  weaken  the 
general  health  of  the  affected  animal.  Hogs  should  be  dipped  twice  at 
intervals  of  ten  days,  every  six  months.  The  pens,  hog  houses,  and 
troughs  should  be  frequently  cleaned  of  all  litter  and  refuse,  and 
strong  solutions  of  one  of  the  various  dips  sprayed  upon  the  premises. 

A  tonic  powder  composed  of  the  following  may  improve  the  general 
health : 

Wood    charcoal 1  part 

Oil    meal 5  parts 

Copperas    2  parts 

Salt    1  part 

Sulphur 1  part 

The  powder  may  be  given  in  doses  of  one  tablespoonful  to  each 
hundred  pounds  of  hogs,  once  a  day  in  the  feed. 

When  cholera  has  already  appeared  in  the  herd  there  is  little  to 
be  done  by  treatment  with  drugs.  There  is  no  known  specific  treat- 
ment for  the  hog  sick  with  cholera.  If  the  money  that  is  spent  for  the 
various  hog  cholera  ' '  cures ' '  that  are  on  the  market,  were  spent  toward 
the  improvement  of  the  hygienic  conditions  and  care  of  hogs,  there  would 
be  fewer  sick  hogs  upon  which  to  use  the  "cures"  and  more  money  in 
the  pocket  of  the  swine  raiser.  It  seems  to  be  characteristic  of  a  large 
part  of  the  hog  raisers  to  give  a  trial  to  all  of  the  "specifics"  that 
are  presented  for  sale  by  various  companies,  instead  of  applying  to 
the  State  Experiment  Station  and  state  authorities  interested  in,  and 
working  toward,  the  preservation  of  the  health  of  animals,  for  infor- 
mation regarding  such  products.  The  State  Experiment  Station  at  all 
times  desires  and  expects  to  give  whatever  advice  possible. 


8  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

Hygienic  measures  are  important  in  checking  outbreaks  of  hog 
cholera.  Dip  the  well  hogs,  separate  them  from  the  sick  hogs,  and 
move  them  to  clean  quarters  at  the  appearance  of  the  disease.  All 
dead  hogs  should  be  burned,  or  covered  with  lime  and  buried  six  feet 
deep.  It  is  better  to  burn  because  there  is  then  no  opportunity  for 
the  carcass  to  be  uncovered  and  infect  the  premises.  If  possible, 
the  well  and  sick  hogs  should  have  different  attendants  and  the  uten- 
sils of  the  sick  should  not  be  used  in  feeding  the  well  hogs.  Cresol 
compound,  U.  S.  P.  (1-20)  or  strong  solutions  of  dips  should  be 
sprayed  around  the  premises  after  the  pens  and  houses  have  been 
cleaned.  The  liberal  use  of  disinfectants,  with  perhaps  a  little  in 
the  feed,  will  do  much  toward  reducing  the  virulence  in  the  sub-acute 
type.  It  is  not  advisable  to  feed  the  sick  hogs  on  a  heavy  ration. 
Feed  them  slops  of  some  ground  feeds.  Good  range  in  good  weather 
is  desirable  but  this  infects  too  large  a  territory  that  is  difficult  to 
disinfect.  After  the  disease  has  run  its  course  the  infected  pens 
should  be  again  thoroughly  disinfected  and  lime  scattered  on  the 
premises.     "Whitewashing  will  do  much  toward  destroying  the  germs. 

Fields  may  be  plowed  and  sowed  to  some  forage  crop  or  they  may 
be  left  free  from  hogs  for  a  few  months.  It  is  not  safe  to  place 
susceptible  hogs  in  infected  pens  within  three  months  after  the  disease 
has  disappeared,  and  even  then  new  infection  may  occur  unless  the 
disinfection  has  been  very  thorough. 

PREVENTION   OF   CHOLERA   BY   HYPER-IMMUNE   SERUM. 

The  great  loss  that  has  been  yearly  sustained  by  the  hog  industry 
through  the  ravages  of  hog  cholera  has  been  the  cause  of  much 
investigation  directed  toward  the  cure  and  prevention  of  the  disease. 
Measures  directed  toward  the  cure  of  hog  cholera  have  been  practically 
fruitless,  but  to  Drs.  Dorset  and  Niles  of  the  United  States  Bureau 
of  Animal  Industry  belongs  the  credit  of  developing  and  making  prac- 
tical the  use  of  a  hyper-immune  serum  to  prevent  hog  cholera.  Soon 
after  field  tests  of  this  serum  had  proved  its  efficiency,  various  state 
experiment  stations  undertook  its  preparation  through  state  appro- 
priations. 

In  response  to  a  demand  by  the  swine  raisers  of  California,  the 
following  bill  was  prepared  and  passed  by  the  State  Legislature  in  1911 : 

An  act  to  provide  for  the  preparation  and  distribution  of  serums  or  vaccines  for  the 

prevention  of  the  disease  known  as  cholera  in  hogs  in  the  State  of  California, 

making  an  appropriation  therefor  and  prescribing  the  duties  of  the  Controller 

and  Treasurer  in  relation  thereto. 

The  People  of  the  State  of  California,  represented  in  Senate  and  Assembly,  do  enact 

as  follows: 
Section  1.     The  Regents  of  the  University  of  California  are  hereby  directed  to 
cause  to  be  prosecuted  with  all  possible  diligence,  through  the  Agricultural  Experi- 


Bulletin  22  9]  H0G    CH0LERA   AND   PREVENTIVE    SERUM.  9 

ment  Station,  the  preparation  of  serums  or  vaccines  that  will  produce  immunity 
in  hogs  against  the  disease  known  as  cholera. 

Sec.  2.  The  Regents  of  the  University  of  California  are  hereby  further 
'authorized  and  directed  to  furnish  such  serums  or  vaccines  in  quantities  not  exceed- 
ing five  hundred  cubic  centimeters  as  soon  as  possible  after  this  act  takes  effect  free 
of  charge  to  any  bona  fide  resident  of  the  State  of  California  who  is  engaged  in  the 
raising  of  hogs,  upon  application  by  such  bona  fide  resident  hog  raiser. 

Sec.  3.  The  Regents  of  the  University  of  California  are  also  hereby  further 
authorized  and  directed  to  furnish  any  bona  fide  resident  of  this  State,  who  is 
engaged  in  the  raising  of  hogs,  such  serums  and  vaccines  in  quantities  in  excess  of 
five  hundred  cubic  centimeters,  upon  the  applicant  paying  therefor  the  actual  cost 
of  production  of  such  serums  or  vaccines. 

Sec.  4.  It  is  herewith  provided  that  no  serums  or  vaccines  shall  be  furnished  free 
of  charge  to  any  one  unless  the  applicant  shall  have  first  furnished  sufficient  evidence 
that  the  disease  known  as  cholera  exists  among  his  hogs  or  among  the  hogs  in  his 
immediate  neighborhood,  and  in  such  case  evidence  shall  be  furnished  by  said  appli- 
cant that  there  is  danger  of  the  disease  being  communicated  to  the  applicant's  hogs. 

Sec.  5.  Any  person  who  shall  sell,  give  away,  or  misuse  any  of  the  serums  so 
furnished  shall,  upon  conviction  thereof  be  deemed  guilty  of  a  misdemeanor,  and  be 
punished  as  in  such  cases  provided  by  law. 

Sec.  6.  The  Director  of  the  Agricultural  Experiment  Station  shall  obtain  and 
establish  such  assistance,  equipment,  materials,  appliances,  apparatus,  and  other 
necesary  incidentals  as  may  be  necessary  to  the  successful  prosecution  of  this  work 
within  the  appropriation  herein  specified. 

Sec.  7.  The  sum  of  sixteen  thousand  ($16,000.00)  dollars  is  hereby  appropriated 
out  of  any  money  in  the  state  treasury,  not  otherwise  appropriated,  six  thousand 
($6,000.00)  dollars  of  which  shall  be  available  for  the  balance  of  the  sixty-second 
fiscal  year  and  ten  thousand  ($10,000.00)  dollars  of  which  shall  be  available  during 
the  sixty-third  and  sixty-fourth  fiscal  years  for  the  use  of  said  Experiment  Station 
to  be  expended  by  the  Regents  of  the  University  of  California  in  carrying  out  the 
purposes  of  this  act,  and  the  State  Controller  is  hereby  authorized  and  directed  to 
draw  his  warrant  for  the  same,  and  the  State  Treasurer  is  hereby  directed  to  pay 
such  warrant. 

Sec.  8.  All  money  appropriated  under  this  act,  and  all  money  received  for  the 
sale  of  said  serums  or  vaccines  as  provided  for  in  section  three  of  this  act,  shall  be 
paid  to  the  Regents  of  the  University  of  California,  and  shall  be  expended  under  the 
direction  of  the  Director  of  the  Agricultural  Experiment  Station  of  said  University 
for  the  specific  purposes  herein  named. 

Six  thousand  dollars  ($6,000.00)  of  the  appropriation  became  avail- 
able June  21,  1911,  but  to  expedite  the  work  of  establishing  the  serum 
plant,  the  Regents  of  the  University  of  California  advanced  three 
thousand  dollars  ($3,000.00)  soon  after  the  Governor  signed  the  bill 
and  the  work  of  preparation  was  prosecuted  with  all  possible  diligence. 

How  the  serum  is  produced. 

Hogs  which  are  naturally  immune  to  cholera  or  are  immune  through 
having  had  the  disease  and  recovered,  are  protected  against  the  cholera 
by  virtue  of  the  presence  in  their  blood  of  invisible  substances  known 
as  "anti-bodies"  which  are  antagonistic  to  the  specific  cause  of  cholera. 
These  anti-bodies  do  not  exist  in  the  simply  immune  hog  in  sufficient 
quantities  to  protect  susceptible  hogs  should  they  be  treated  with 
blood  from  the  immunes,  unless  very  large  quantities  of  blood  should 
be  used.  To  increase  the  amount  of  these  anti-bodies  in  the  blood  of 
the  immune  hog,  the  hog  is  injected  with  quantities  of  virulent  hog 
cholera  blood,  which  stimulates  the  cells  of  the  body  to  throw  off  a 


10  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

larger  amount  of  anti-bodies.  The  process  is  known  as  hyper-immun- 
lzing,  and  the  hog  so  treated,  as  the  hyper-immnne.  The  hyper-immune 
furnishes  the  serum  which  is  used  to  protect  susceptible  hogs.  For 
this  purpose  vigorous  hogs  weighing  from  150  to  300  pounds  are 
used.  If  they  are  not  already  immune  these  hogs  must  be  treated 
with  a  small  quantity  of  hog  cholera  virus  and  the  protective  serum. 
To  test  the  immunity  from  this  treatment,  a  preliminary  dose  of  hog 
cholera  virus  is  injected  into  these  pigs  in  about  ten  days  after  the 
protective  dose.  In  ten  da}^s  more  these  are  ready  to  be  made  hyper- 
immune.    This  process  may  be  carried  on  in  several  different  ways. 

In  the  intra-venous  method  one  injection  of  5  c.c.  to  the  pound  of 
hog,  of  virulent  hog  cholera  blood  is  injected  into  a  vein  in  the  ear. 
A  200  pound  hog  requires  a  quart  at  one  injection  by  this  method. 

In  the  intra-abdominal  method,  one  injection  of  about  8  c.c.  to  the 
pound  of  hog  is  injected  into  the  abdominal  cavity. 

In  the  subcutaneous  method,  one  injection  of  10  c.c.  per  pound  of 
hog  is  injected  underneath  the  skin. 

In  the  slow  subcutaneous  three  injections  are  given  at  intervals  of 
one  week  at  the  rate  of  1  c.c.  per  pound  at  the  first,  3  c.c.  per  pound 
at  the  second,  and  5  c.c.  per  pound  at  the  third  injection.  In  about 
ten  days  after  treatment  by  any  of  these  methods,  the  hyper-immune 
is  ready  to  be  bled  the  first  time  and  thereafter  at  intervals  of  one 
week  until  four  bleedings  have  been  taken.  Bleeding  of  the  hyper- 
immune is  accomplished  by  cutting  off  a  small  portion  of  his  tail  at 
each  bleeding.  The  flow  of  blood  is  stopped  by  a  string  ligature 
around  the  end  of  the  tail.  After  four  bleedings  the  hyper-immune 
may  be  rehyper-immunized.  Bleeding  and  hyper-immunizing  may  be 
continued  as  long  as  there  is  tail  remaining.  When  the  hog  cannot 
be  bled  longer  from  the  tail,  all  of  the  blood  is  taken  by  severing  the 
jugular  vein  or  carotid  artery.  These  hogs  are  fit  for  food,  subject 
of  course  to  post-mortem  inspection  for  abnormal  conditions.  After 
the  blood  is  drawn  from  the  tail  the  clot  is  removed,  the  blood  serum 
and  corpuscles  that  remain  are  mixed  with  carbolic  acid  solution  to  one- 
half  per  cent  acid.  A  200  pound  hyper-immune  may  furnish  from 
1000  to  1200  c.c.  of  serum  at  one  bleeding. 

The  serum  must  be  stored  in  a  cool  place  at  a  temperature  not 
above  55°  F.  Serum  kept  in  a  cold  place  will  remain  potent  for  a 
year  or  more. 

In  order  to  obtain  the  large  quantity  of  hog  cholera  virus  that  is 
necessary  to  produce  the  hyper-immune,  young  and  healthy  susceptible 
shotes  weighing  from  50  to  100  pounds  are  injected  with  virus  and 
should  be  ready  to  be  killed,  and  their  blood  collected  at  the  most 
virulent  stage  of  acute  cholera,  in  from  seven  to  fifteen  days.  Inocu- 
lated shotes  that  linger  longer  than  fifteen  days  usually  develop  the 


Bulletin  229] 


HOG    CHOLERA    AND   PREVENTIVE    SERUM. 


11 


chronic  form  of  cholera,  and  such  blood  does  not  produce  potent 
serum.  The  virulent  blood  must  be  collected  and  handled  in  the  most 
careful  manner  to  prevent  contamination  with  germs  that  may  kill 
the  hyper-immune  into  which  the  blood  is  injected.     Virulent  blood 


Fig.    4. — Bleeding   a   sick   hog   to   obtain   cholera 
blood   (virus)    for  hyper-immunizing. 


used  for  hyper-immunizing,  must  not  be  over  twenty-four  hours  old 
and  must  be  stored  in  a  cool  place  if  not  used  immediately. 

The  addition  of  one  half  per  cent  carbolic  acid  solution   does  not 
destroy  the  hog  cholera  virus.      This  has  been   demonstrated  in  the 


12 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


laboratory  and  is  of  considerable  value  in  collecting  hog  cholera  blood 
from  outbreaks  when  the  virus  cannot  be  used  immediately.  Virus 
collected  in  the  field  and  preserved  in  this  way  may  be  used  with 
safety  in  the  slow  subcutaneous  method  of  hyper-immunizing.  Virus 
used  for  simultaneous  inoculations  should  contain  from  one-fourth  to 
one-half  per  cent  carbolic  acid  to  prevent  septic  infection.  Experi- 
ments are  in  progress  in  using  formalin  as  a  suitable  preservative  for 
virus  intended  for  intra-venous  or  intra-abdominal  injections. 


Fig.  5. — View  of  part  of  the  hyper-immune  pens. 

Potency  of  serum. 

All  serum  distributed  by  the  California  Station  is  carefully  tested 
for  potency  before  it  is  sent  from  the  laboratory.  This  is  done  in 
the  following  manner:  The  blood  serum  of  several  hyper-immunes  is 
mixed.  Six  pigs  weighing  from  50  to  100  pounds  are  injected  intra- 
muscularly with  2  c.c.  each  of  virulent  hog  cholera  blood.  Each  of 
two  of  these  is  given  15  c.c.  of  the  mixed  sera  to  be  tested.  Two 
others  are  given  20  c.c.  each  of  the  mixed  sera  to  be  tested.  If  all 
those  receiving  immunizing  serum  continue  in  good  health  and  the 


Bulletin 


HOG    CHOLERA    AND    PREVENTIVE    SERUM. 


13 


two  checks  become  ill  of  cholera  within  eight  days  and  are  apparently 
going  to  die  within  fifteen  days,  the  serum  is  considered  suitable  for 
field  use  in  doses  of  20  c.c.  for  hogs  weighing  from  50  to  100  pounds. 


Fig.  6. — Proper  way  to  hold  and  vaccinate  a  shote. 

If  one  or  both  of  the  pigs  receiving  15  c.c.  of  the  serum  become 
obviously  sick  of  cholera, and  the  two  pigs  receiving  20  c.c.  each  of  the 
immunizing  serum  both  continue  in  good  health,  then  the  serum  may 
be  used  in  field  work  in  suitably  increased  doses. 


14  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

Methods  of  using  hyper-immune  serum. 

The  success  of  the  treatment  of  hogs  with  hyper-immune  sera  depends 
not  only  upon  the  careful  and  scientific  method  of  preparation,  but 
also  upon  its  intelligent  administration.  The  Experiment  Station 
assumes  no  responsibility  for  the  results  of  the  use  of  the  sera  which 
it  distributes.  It  is  recommended  that  wherever  possible  competent 
and  qualified  veterinarians  should  be  engaged  to  administer  the  serum. 
However,  an  intelligent  hog  owner,  by  observing  strict  attention  to 
directions  which  are  sent  with  orders  for  serum,  may  expect  satisfactory 
results  from  the  treatment  with  protective  serum. 

The  serum  is  a  preventive,  not  a  cure,  for  hog  cholera,  and  should 
not  be  given  to  hogs  already  sick  with  cholera.  It  is  a  preventive  to 
hog  cholera  only,  and  cannot  be  expected  to  prevent  hogs  from  becom- 
ing sick  from  other  conditions.  A  correct  diagnosis  is  therefore 
demanded  to  protect  the  serum,  and  prevent  its  useless  administration 
in  herds  sick  from  some  other  cause. 

There  are  two  methods  of  using  hyper-immune  serum,  viz.,  the 
"Serum  Alone"  and  the  "Serum  Simultaneous." 

Serum  alone. 

This  method  is  recommended  to  be  used  in  an  already  infected  herd, 
upon  apparently  healthy  hogs  only.  Inject  deeply  into  the  muscles 
of  the  inside  of  the  ham  the  proper  dose  of  serum  only.  This  method 
gives  only  temporary  immunity,  lasting  from  six  weeks  to  three  months 
if  the  hog  is  not  exposed  to  infectious  material  in  the  mean  time. 
Should  the  immunized  hog  be  immediately  exposed  to  infection  after 
treatment  the  result  would  be  a  more  permanent  immunity  conferred. 

This  method  is  also  useful  in  giving  temporary  immunity  to  valuable 
pure  bred  hogs  before  shipping  to  fairs. 

Although  it  may  be  desirable  to  allow  the  treated  hogs  to  mix  with 
the  diseased  because  of  a  possibility  of  a  longer  immunity  being  con- 
ferred, it  must  not  be  overlooked  that  so  long  as  the  sick  hogs  are  not 
destroyed  and  the  infected  pens  are  not  disinfected,  there  is  a  center 
existing  for  continuous  opportunity  for  the  infection  to  be  carried 
to  other  parts  of  the  neighborhood.  It  is  further  advised  that  if 
disinfection  of  the  pens  and  destruction  of  the  sick  hogs  are  not  carried 
on  at  the  beginning  of  an  outbreak,  that  it  certainly  be  done  as  soon  as 
the  herd  shows  evidence  that  the  disease  is  checking,  because  of  the 
possibility  that  the  treated  hogs  have  not  been  sufficiently  exposed  to 
the  infected  material  during  the  outbreak  to  give  them  a  longer  immu- 
nity than  the  serum-alone  treatment  might  have  given  them,  which 
is  probably  from  six  weeks  to  three  months. 

All  immunized  hogs  should,  however,  either  be  kept  separate  from 
the  untreated  or  be  marked  in  some  way  so  that  the  results  of  the 


Bulletin  229] 


HOG  CHOLERA  AND   PREVENTIVE  SERUM. 


15 


serum  may  be  accurately  known.  Before  treatment  it  is  imperative 
that  the  well  hogs  be  kept  away  from  the  sick  ones  and  disinfection 
carried  on.     The  dead  hogs  should  at  all  times  be  immediately  burned. 


Fig.  7. — A  method  of  vaccinating  a  heavy  hog. 

Serum  simultaneous. 

This  method  gives  a  more  lasting  immunity  but  is  attended  with 
some  danger,  unless  the  treatment  is  administered  by  a  person  who 
thoroughly  understands  the  precautions  necessar}7.  For  the  present 
only    qualified    veterinarians    will    be    allowed    to    use    this    method. 


3  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 

This  is  for  the  purpose  of  minimizing  any  bad  results.  In  using  this 
method,  from  one-half  to  one  cubic  centimeter  of  virulent  hog  cholera 
blood  is  injected  into  the  muscles  of  the  inside  of  the  ham  on  one  side, 
while  at  the  same  time  the  proper  dose  of  hyper-immune  serum  is 


Fig.  8. — Sows  heavy  with  pig  may  be  snubbed  to  a  post  and  vaccinated  without, 
throwing. 

injected  into  the  opposite  ham,  in  the  same  manner  as  described 
under  ' '  Serum  Alone. ' '  This  method  is  recommended  for  non-infected 
herds,  or  it  may  be  used  upon  recently  infected  herds,  upon  hogs  that 
do  not  show  a  temperature  higher  than  103.5°  F. 


Bulletin-  229]  H0G    CHOLERA   AND   PREVENTIVE    SERUM.  17 

It  is  the  method  to  use  when  the  swine  raiser  wishes  to  immunize 
his  herd  when  infection  has  not  yet  taken  place,  provided  the  entire 
herd  is  treated.  While  the  loss  is  less  than  one-tenth  of  one  per  cent 
from  this  method,  the  entire  herd  must  be  immunized  because  of  the 
danger  to  untreated  hogs  in  case  cholera  is  produced  in  a  few  of  the 
treated  hogs.  Where  all  hogs  are  not  treated  by  this  method  the 
immunized  hogs  should  be  kept  in  strict  quarantine  for  two  weeks  to 
give  time  for  development  of  any  cases  of  cholera.  It  is  valuable  to 
use  on  all  breeding  stock  because  the  offspring  of  immune  sows  has 
been  shown  to  possess  a  slight  immunity  up  to  four  or  six  weeks. 
After  this  time  the  pigs  themselves  may  be  given  a  lasting  immunity 
by  this  method  of  treatment.  It  is  not  advisable  to  use  the  simul- 
taneous method  upon  pigs  under  six  weeks  of  age.  Wherever  possible 
this  manner  of  treatment  should  be  used,  but  only  by  persons  who 
thoroughly  understand  the  technique  and  the  dangers.  The  Experi- 
ment Station  will  aid  in  every  way  possible,  so  long  as  funds  are 
available,  in  assisting  the  use  of  the  serum  and  the  virus.  A  list  of 
qualified  veterinarians  is  kept  so  that  the  station  is  able  to  recommend 
competent  men  who  may  be  employed  to  use  this  treatment. 

Properly  prepared  serum,  when  used  alone,  without  the  employ- 
ment of  blood  from  a  sick  hog,  is  entirely  harmless  and  incapable  of 
giving  rise  to  an  attack  of  hog  cholera.  Nor  does  this  injection  inter- 
fere in  any  way  with  the  growth  of  the  treated  hogs. 

Administering  the  serum. 

Always  act  promptly  upon  the  appearance  of  cholera.  After  the 
disease  is  well  settled  in  the  herd  it  does  little  good  to  vaccinate. 

The  inside  of  the  ham  should  be  thoroughly  washed  with  a  3  per  cent 
lysol,  creolin,  or  carbolic  acid  solution  before  making  the  injection. 
Failure  to  do  this  may  result  in  abscess  and  necrosis  of  the  muscles. 

Very  heavy  hogs,  and  sows  heavy  with  pig,  may  be  snubbed  up  to 
a  corner  and  the  injection  made  into  the  ham  from  the  rear.  Others 
may  be  held  up  by  the  hind  legs  or  thrown  to  the  ground.  Figs.  6, 
7,  and  8  show  methods  of  handling. 

All  instruments  and  glassware  used  in  the  treatment  must  be 
previously  sterilized  by  boiling.  The  syringe  should  be  kept  in  disin- 
fectant while  not  in  actual  use  in  injecting  serum. 

Avoid  sticking  the  bone  in  making  injections.  A  short,  stout,  slip 
needle  on  the  syringe  will  help  to  prevent  this  accident,  and  also  reduce 
the  possibility  of  breaking  the  needle. 

Open  only  one  bottle  of  serum  at  a  time.  If  it  is  necessary  to  keep 
the  serum  for  a  time  before  using,  it  should  be  kept  in  a  cool,  dark  place 
or  upon  ice. 

Vessels  containing  serum  and  virulent  blood  should  be  kept  covered 
during  the  operation  to  prevent  contamination  from  the  air  and  dust. 


18 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


Do  not  use  serum  for  virus  or  virus  for  serum. 

Do  not  underestimate  the  weight  of  the  hog  to  save  serum.  A  small 
amount  may  not  protect  while  an  overdose  does  no  harm. 

Should  any  virulent  blood  be  spilled  during  the  operation,  imme- 
diately cover  it  with  disinfectant.  Destroy  that  remaining  after  treat- 
ment by  increasing  its  volume  several  times  with  a  strong  disinfectant. 

Use  separate  syringes  for  virulent  blood  and  serum. 

Do  not  release  the  hog  until  the  operation  has  been  completed.  The 
point  of  injection  should  be  wiped  with  disinfectant  and  made  certain 
that  no  serum  or  virus  is  oozing  from  the  point  of  injection  before  the 
operation  can  be  considered  complete. 

Subsequent  to  treatment  the  hogs  should  not  be  allowed  to  lie  in 
muddy  and  filthy  pens. 


Fig.    9. — A   group   of   virus   houses   for   sick   hogs.      Incinerator   at   the    left. 

Equipment  necessary. 

A  reliable  graduated  syringe  holding  20  c.c.  and  possessing  a  stout, 
short  slip  needle.  (These  may  be  obtained  by  applying  to  the  Director 
of  the  Experiment  Station.     Prices  range  from  $2.00  to  $5.00  each.) 

A  smaller  syringe  holding  from  5  to  10  c.c.  for  use  with  virulent 
blood. 

A  pint  Mason  jar  or  tumbler  to  hold  the  serum. 

A  smaller  vessel  for  holding  virulent  blood. 

A  quantity  of  disinfectant  solution  and  a  cloth. 


Bulletin 


19] 


HOG  CHOLERA  AND  PREVENTIVE  SERUM. 


19 


Table  of  Doses. 

Weight  of  hogs.  Dose  of  serum.  Dose  of  virus. 

Sucking  pigs_' 10  to  15  c.  c \  c.  c. 

30  to  50  pounds 15  to  20  c.  c !_ 1  c.  c. 

50  to  100  pounds 20  to  30  c.  c 1  c.  c. 

100  to  150  pounds 30  to  35  c.  c 1  c.  c. 

150  to  200  pounds 35  to  40  c.  c 1  c.  c. 

200  to  250  pounds 40  to  45  c.  c 1  c.  c. 

Over  300  pounds GO  to  70  c.  c 1  c.  c. 

In    badly    infected    herds    this    dosage    should    always    be    slightly 
increased. 
Do  not  give  serum  to  a  sick  hog. 

How  to  secure  the  serum. 

In  compliance  with  the  state  law  in  regard  to  the  distribution  of 
serum,   all  serum  must  be  sent   directly  to  the  resident  hog  raiser. 


ac .  '-"^gj^iwpi 

Fig.    10. — Equipment  necessary  for   immunizing. 

Veterinarians  who  are  using  it  for  clients  should  have  the  client  make 
application  for  the  serum  in  his  own  name  together  with  that  of  the 
veterinarian.  The  serum  can  not  be  secured  without  the  signature  of 
the  veterinarian.  Five  hundred  cubic  centimeters,  enough  for  about  20 
shotes,  weighing  from  50  to  80  pounds,  are  distributed  free  of  charge 
only  upon  properly  signed  application  received  from  a  hog  owner  when 
there  is  cholera  present  in  his  herd,  or  when  his  hogs  are  in  immediate 
danger  from  the  disease.  -A  veterinarian  must  sign  such  applications 
or  other  suitable  evidence  must  be  given  that  the  disease  exists  in  the 
herd  or  is  in  the  immediate  vicinity.  All  applications  for  serum  should 
be  made  out  on  blanks  furnished  for  that  purpose.     These  application 


20  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

blanks  may  be  obtained  by  writing  to  the  Director  of  the  Agricultural 
Experiment  Station,  Berkeley,  California,  to  the  Veterinary  Department 
of  the  University  of  California,  Berkeley,  California,  or  to  the  State 
Veterinarian,  Sacramento,  California.  Copies  have  been  sent  to  the 
County  Live  Stock  Inspectors  in  the  various  counties  having  such 
officials,  and  an  effort  has  been  made  to  place  application  blanks  in  the 
hands  of  as  many  hog  raisers  and  veterinarians  as  possible. 

In  cases  of  emergency,  when  no  application  blanks  are  available, 
the  form  given  on  the  last  page  of  this  bulletin  may  be  filled  out  and 
sent  to  the  Director  of  the  Experiment  Station,  Berkeley,  California. 
In  cases  where  a  night  letter  or  a  telegram  is  necessary,  the  following 
form  should  be  used : 

Veterinary  Department,  University  of  California, 
Berkeley,  California: 
Send  hog  serum  to 

(Insert  name  of  express  office  here) 

for hogs,  total  weight 

(Number  of  hogs)  (Total  weight  in  pounds) 

Before  using  serum,  I  agree  to  fill  out,  sign,  and  mail 
to  you  the  application  blanks  furnished  with  serum.  I 
am  a  resident  of  California. 

(Signed)         

(Signature  of  owner  of  hogs) 
Cost  of  the  serum. 

All  serum  is  sold  at  actual  cost  of  production,  except  that  distributed 
free  as  provided  by  law.  When  the  laboratory  first  began  the  prepara- 
tion of  hyper-immune  serum  the  cost  was  approximated  at  2J  cents  per 
c.c,  making  the  cost  of  treatment  of  a  50  to  60  pound  shote  about  50 
cents.  With  a  larger  quantity  of  serum  now  being  made  and  improved 
facilities  for  production  established,  it  has  been  found  that  the  cost  of 
serum  can  be  slightly  decreased,  and  will  be  placed  at  2  cents  per  c.c. 
after  September  1,  1912.  It  is  evident  upon  study  of  the  method  of 
making  the  serum,  that  a  large  number  of  hogs  are  consumed.  The 
price  of  these  varies  as  does  the  feed  which  is  necessary  for  these 
animals.  Competent  veterinarians  and  assistants  are  necessary  in  order 
to  produce  a  reliable  product.  Every  effort  is  made  toward  the  practice 
of  economy  and  different  methods  are  used  which  might  reduce  the  cost 
of  production  and  at  the  same  time  produce  a  potent  serum.  The  use  of 
normal  salt  solution  placed  in  the  abdominal  cavity  of  the  virus  hogs  a 
few  hours  before  death  and  recovered  at  the  time  of  killing,  has  given 
success  and  reduced  the  cost  of  making  a  hyper-immune.  Virulent 
blood  is  collected  from  field  outbreaks  in  justifiable  cases. 


UNIVERSITY   OP    CALIFORNIA — EXPERIMENT   STATION. 


21 


Serum  produced. 

From  September  1,  1912,  to  June  1,  1912,  the  Station  has  produced 
600,000  c.c.  of  serum,  which  is  enough  to  vaccinate  24,000  one  hundred 
pound  hogs.  This  has  supplied  the  demand  except  in  a  few  instances 
where  a  few  days  were  required  until  the  serum  could  be  tested  before 
it  was  shipped.  To  produce  this  amount  of  serum  has  required  174 
hyper-immune  hogs.  To  produce  these  hyper-immunes  230  susceptible 
hogs  were  used  to  secure  the  virulent  blood.  Two  hundred  thirteen 
thousand  cubic  centimeters  or  thirty- eight  per  cent  of  the  serum  has 
been  distributed  free  of  cost  to  the  hog  raisers  according  to  the  direction 
of  the  law. 

Results  of  the  serum  in  California. 

Hog  cholera  has  been  reported  and  serum  used  in  the  following 
counties : 

Alameda  Nevada 

Butte  Napa 

Colusa  Orange 

Fresno  Placer 

Glenn  San  Luis  Obispo 

Imperial  Santa  Cruz 

Kings  Sacramento 

Kern  San  Diego 

Los  Angeles  Sonoma 

Only  thirty-seven  complete  reports  have  been  received  of  the  outcome 
cf  the  serum  treatment  in  infected  herds.  The  following  table  gives 
the  summary  of  these  results: 


Shasta 

San  Joaquin 

Solano 

San  Bernardino 

Sutter 

San  Mateo 

Tulare 

Tehama 

Yolo 


Number     of 
herds. 

Number    of 
hogs 
treated. 

Number     that     died     after 
treatment,   apparently  well 
when  treated. 

Number    dead    at    time 
application   was   made 
for  serum. 

Per    cent    of 

treated     hogs    that 

died. 

37 

2,760 

363 

813 

13  +  % 

It  must  be  remembered  that  these  reports  are  from  infected  herds, 
the  majority  showing  the  acute  type  of  the  disease.  Many  of  the 
13  +  per  cent  were  no  doubt  infected  and  not  yet  showing  visible 
symptoms  when  injected  with  the  serum.  Nine  outbreaks  out  of  the 
37  were  abruptly  checked.  The  serum  should  not  be  wasted  on  visibly 
sick  hogs. 

Reports  necessary. 

Blank  report  forms  are  distributed  with  every  order  of  serum  but 
very  few  of  them  are  returned  to  the  Station  with  the  data  necessary. 
These  reports  are  desired  in  order  that  the  Station  may  have  a  record 
of  the  results  of  the  serum  treatment.  These  records  are  important 
because  the  serum  is  distributed  directly  to  the  hog  raisers  and  the 
Station  has  no  other  way  of  determining  whether  the  serum  has  been 
used  properly  and  whether  it  is  doing  the  good  that  is  expected  of  it. 


22  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

APPLICATION  BLANK  FOR  ANTI-HOG  CHOLERA  SERUM. 


To  the  Director  of  the  Agricultural  Experiment  Station,  Town 

University  of  California,  Berkeley,  Cal.:  Date 

Sir:  I  have  read  Circular  No.  68  (or)  Bulletin  No.  229  (indicate  which  by 
underlining),  issued  by  the  Agricultural  Experiment  Station,  University  of  Cali- 
fornia, and  desire  to  have  my  hogs  immunized  with  serum  prepared  by  said  Experi- 
ment Station. 

I  am  a  bona  fide  resident  of  the  State  of  California  and  am  actually  engaged  in 

hog  raising. 

My  post  office  address  is 

(Town)  (County) 

The  total  number  of  hogs  on  my  premises  is 

Of  which  the  number  weighing  less  than  20  pounds  that  I  wish  to  treat  is 

The  number  weighing  from  20  to  50  pounds  that  I  wish  to  treat  is 

The  number  weighing  from  50  to  100  pounds  that  I  wish  to  treat  is : 

The  number  weighing  from  100  to  150  pounds  that  I  wish  to  treat  is 

The  number  weighing  from  150  to  200  pounds  that  I  wish  to  treat  is 

The  number  weighing  from  200  to  250  pounds  that  I  wish  to  treat  is 

The  number  weighing  over  300  pounds  that  I  wish  to  treat  is 

The  total  estimated  weight  of  all  my  hogs  that  I  wish  to  immunize  is 

I  understand  that  the  Agricultural  Experiment  Station  assumes  no  responsibility 
for  the  serum  which  it  distributes  further  than  that  great  care  is  exercised  in  its 
preparation  and  in  testing  it  for  potency  before  it  leaves  the  laboratory. 

I  agree  to  report  in  writing,  on  blanks  to  be  furnished  with  the  serum,  the 
results  of  the  serum  treatment  of  my  hogs  to  the  Director  of  the  Experiment 
Station  once  each  week  for  four  consecutive  weeks. 

( Signed)  

(Owner  of  the  hogs) 

(If  hog  cholera  exists  in  your  herd  or  in  the  immediate  neighborhood  the  follow- 
ing blanks  should  be  filled  in.) 

Date  of  first  indication  of  cholera  in  your  herd . 

Date  of  first  death  from  cholera  in  your  herd 

Sizes  of  hogs  that  seem  to  be  particularly  affected 

The  approximate  length  of  sicknesses 

Number  of  hogs  sick  with  cholera  at  the  present  time 

Number  of  hogs  that  have  died  from  cholera  in  the  present  outbreak 

Has  cholera  existed  on  your  premises  before? When? | 

To  the  best  of  my  knowledge  the  nearest  infected  hogs  are 

miles  distant  from  my  premises,  on  the  ranch  of » 

whose  post  office  address  is : 

I  have  reason  to  believe  that  my  hogs       ^re  not    in     immediate     danger     from     hog 

cholera. 

Signature  of  owner  of  the  hogs 

Signature  of  veterinarian  who  made  the  diagnosis  of  cholera 

Signature  of  veterinarian  who  is  to  administer  the  serum 

(Make  all  checks,  money  orders,  and  drafts  payable  to  the  Regents  of  the  Univer- 
sity of  California.     Do  not  send  cash   in   payment  for  serum.) 


STATION     PUBLICATIONS     AVAILABLE     FOR     DISTRIBUTION. 


REPORTS. 

1896.  Report  of  the  Viticultural  Work  during  the  seasons  1! 

ing  the  Vintages  of  1894-95. 

1897.  Resistant  Vines,    their   Selection,    Adoption,    and   Graf  tin 

cultural  Report  for  1896. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-03. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-04 


7-93,  with  data  regard- 
Appendix   to   Viti- 


BULLETINS. 


Reprint. 
No.   128. 

133. 

147. 

162. 

164. 

167. 

168. 

169. 

170. 

171. 

174. 
176. 

177. 


178. 
179. 


181. 

182. 


183. 
184. 


185. 


186. 

187. 


188. 


189. 


191. 
192. 


193. 


Endurance   of   Drought   in    Soils 

of  the  Arid  Regions. 

Nature,  Value,  and  Utilization 
of  Alkali  Lands,  and  Toler- 
ance of  Alkali.  (Revised 
and  Reprinted,  1905.) 

Tolerance  of  Alkali  by  Various 
Cultures. 

Culture  Work  of  the  Sub-sta- 
tions. 

Commercial  Fertilizers.  (Dec. 
1,    1904.) 

Poultry  Feeding  and  Proprie- 
tary Foods. 

Manufacture  of  Dry  Wines  in 
Hot    Countries. 

Observations  on  Some  Vine 
Diseases  in  Sonoma  County. 

Tolerance  of  the  Sugar  Beet 
for  Alkali. 

Studies  in  Grasshopper  Con- 
trol. 

Commercial  Fertilizers.  (June 
30,    1905.) 

A    New    Wine-cooling    Machine. 

Sugar  Beets  in  the  San  Joaquin 
Valley. 

A  New  Method  of  Making  Dry 
Red   Wine. 

Mosquito   Control. 

Commercial  Fertilizers.  (June, 
1906.) 

The  Selection  of  Seed- Wheat. 

Analyses  of  Paris  Green  and 
Lead  Arsenate.  Proposed  In- 
secticide Law. 

The    California    Tussock-moth. 

Report  of  the  Plant  Pathologist 
to  July  1,   1906. 

Report  of  Progress  in  Cereal 
Investigations. 

The  Oidium  of  the  Vine. 

Commercial  Fertilizers.  (Janu- 
ary,   1907.) 

Lining  of  Ditches  and  Reser- 
voirs to  Prevent  Seepage 
Losses. 

Commercial  Fertilizers.      (June, 

1907.) 

California  Peach  Blight. 

Insects  Injurious  to  the  Vine  in 
California. 

The  Best  Wine  Grapes  for  Cali- 
fornia ;  Pruning  Young  Vines  ; 
Pruning  the  Sultanina. 


No.    194.     Commercial   Fertilizers.      (Dec, 
1907.) 
195.     The      California     Grape     Root- 
worm. 

197.  Grape     Culture     in     California; 

Improved  Methods  of  Wine- 
making  ;  Yeast  from  Califor- 
nia Grapes. 

198.  The    Grape    Leaf-Hopper. 

199.  Bovine   Tuberculosis. 

200.  Gum    Diseases    of    Citrus    Trees 

in    California. 

201.  Commercial   Fertilizers.      (June, 

1908.) 

202.  Commercial       Fertilizers.      (De- 

cember,   1908.) 
20  3.     Report  of  the  Plant  Pathologist 
to  July  1,  1909. 

204.  The    Dairy    Cow's    Record    and 

the  Stable. 

205.  Commercial     Fertilizers.       (De- 

cember,   1909.) 

206.  Commercial    Fertilizers.      (June, 

1910.) 

207.  The    Control    of    the    Argentine 

Ant. 

208.  The    Late   Blight   of   Celery. 

209.  The   Cream   Supply. 

210.  Imperial  Valley  Settlers'  Crop 
Manual. 

211.  How  to  Increase  the  Yield  of 
Wheat  in  California. 

212.  California   White   Wheats. 

213.  The  Principles  of  Wine-making. 

214.  Citrus  Fruit  Insects. 

215.  The  Housefly  in  its  Relation  to 
Public   Health. 

216.  A  Progress  Report  upon  Soil 
and  Climatic  Factors  Influenc- 
ing the  Composition  of  Wheat. 

217.  Honey  Plants  of  California. 

218.  California   Plant   Diseases. 

219.  Report  of  Live  Stock  Conditions 
in  Imperial  County,  California. 

220.  Fumigation  Studies  No.  5  ;  Dos- 
age Tables. 

221.  Commercial  Fertilizers.  (Oct., 
1911.) 

222.  The  Red  or  Orange  Scale. 

223.  The  Black  Scale. 

224.  The  Production  of  the  Lima 
Bean. 

225.  Tolerance  of  Eucalvptus  for 
Alkali. 

226.  The  Purple  Scale. 

227.  Grape  Vinegar. 

228.  Pear  Thrips  and  Peach  Tree 
Borer. 


CIRCULARS. 


No.      1.  Texas  Fever. 

7.  Remedies  for  Insects. 
9.  Asparagus  Rust. 

10.  Reading  Course  in  Economic  En- 

tomology. 

11.  Fumigation  Practice. 

12.  Silk  Culture. 

15.  Recent  Problems  in  Agriculture. 
What  a  University  Farm  is  For. 

29.  Preliminary    Announcement    Con- 

cerning Instruction  in  Practical 
Agriculture  upon  the  University 
Farm,  Davis,  Cal. 

30.  White  Fly  in  California. 

32.  White  Fly  Eradication. 

33.  Packing    Prunes    in    Cans.     Cane 

Sugar  vs.  Beet  Sugar. 

36.  Analyses  of  Fertilizers  for  Con- 
sumers. 

39.  Instruction  in  Practical  Agricul- 
ture at  the  University  Farm. 

46.  Suggestions  for  Garden  Work  in 
California  Schools. 

50.  Fumigation  Scheduling. 

52.  Information  for  Students  Concern- 
ing the  College  of  Agriculture. 


No.  55.  Farmers'  Institutes  and  Univer- 
sity Extension  in  Agriculture. 

Experiments  with  Plants  and  Soils 
in  Laboratory,  Garden,  and 
Field. 

Butter  Scoring  Contest,   1910. 

University  Farm   School. 

The  School  Garden  in  the  Course 
of  Study. 

How  to  Make  an  Observation  Hive. 

Announcement  of  Farmers'  Short 
Courses  for  1911. 

The  California  Insecticide  Law. 

66.  Insecticides  and  Insect  Control. 

67.  Development  of  Secondary  School 
Agriculture  in  California. 

The    Extermination    of    Morning- 

Glory. 
Observation  of  the  Status  of  Corn 

Growing  in  California. 
A  New  Leakage  Gauge. 
Hot  Room  Callusing. 
University  Farm  School. 
Announcement  of   Farmers'   Short 
Courses  for  1912. 
79.  List  of  Insecticide  Dealers. 
74.  Rice. 


58. 


60. 
61. 
62. 

63. 
64. 

65. 


69. 

70. 

75. 
76. 
77. 
78. 


